DIY - M3 Strut Brace the Cheap Way In 2025

[jasonjoyrides]

If you have adjustable coilovers installed on your 1er, you know that the stock strut brace is rather annoying because it does not allow you to adjust the damping without removing it. This issue has been remedied in previous years by either installing an OEM 1M brace, or buying HP Autosport's M3 strut brace. The issue with these, for me, is that the HP Autosport kit is far too expensive ($730) for my budget, and the 1M brace isn't much better ($550). So I decided to buy an Original M3 strut brace off of a partout for $300. These can also be found on eBay for the same price. I made a video showing the whole project (linked below), but am also typing this out here for you to reference.

https://www.youtube.com/watch?v=MSQFeEfFMRY

What you need:
The kit should hopefully come with the center bracket, the heater closing panel, both strut tower mounting rings, both cross members, and all hardware. If it does not come with a heater closing panel, keep in mind that you will either need to modify yours to work or you will need to buy a new M3 one with the rubber boots that clip in. If you want to refresh your hardware, you will need to buy that as well.

Reference this kit for hardware part numbers: https://www.fcpeuro.com/products/bmw...BoCtYIQAvD_BwE

Installation:
The installation is straight forward until you reach the center bracket. The firewall on the 1 series is steeper than the 3 series, so the M3 piece ends up pointing down too far. What I ended up doing is clamping the piece in a bench vise using two scrap 2x4s as insulation and using a propane torch to heat it up. Once it got to about 480 degrees Fahrenheit, I used the top pipe end of my jack handle to bend the arms to the appropriate angle. After bending, the mounting points were no longer parallel with each other, so I heated again and used vise grips to twist them.

I also grinded down the studs and nuts on the end of the brace closest to the strut tower because they were interfering with the cowl. I also used a flappy disc on my grinder to take away some material on the cowl to help it fit flush.

The rest of the install is as straight forward as it could be. My word of advice would be to only tighten all hardware to finger tight first, and then once all of them are in place, go back and tighten them completely. The 13mm hardware on the strut tower and cross members are all torqued to 25 ft-lbs (34 Nm), and the center E18 socket bolt is torqued to 74 ft-lbs (100 Nm). Also, I found it easier to remove and install the heater closing panel by removing the right windshield wiper and popping up that panel. All of this is shown in the video.

Notes:
When I bent my center bracket, I took note of any surface cracks or imperfections that could have resulted. Mine looked perfect after, so I am confident that the structural integrity has not been compromised. I do advise you that I am not a material scientist though so doing this is at your own risk. I am not responsible if you experience a mechanical failure.

Hope this helps anyone looking for an affordable optioin for this upgrade! Feel free to ask any questions.

[ZHPizza]

Awesome! I picked up a used M3 brace a few months ago with hopes that I could heat/bend the center bracket to fit, but hadn't yet seen anyone attempt it. Can't thank you enough for (1) being the guinea pig on this method and (2) sharing the results!

[jasonjoyrides]

Originally Posted by ZHPizza

Awesome! I picked up a used M3 brace a few months ago with hopes that I could hear/bend the center bracket to fit, but hadn't yet seen anyone attempt it. Can't thank you enough for (1) being the guinea pig on this method and (2) sharing the results!

Sweet man! I am truly surprised to be the first to document this. Post up pics when you finish!

[Suprgnat]

Originally Posted by jasonjoyrides

the HP Autosport kit is far too expensive ($730) for my budget

Damn! It was $396.65 back in 2013 when I bought it, and I thought that was pricy. Where were you then when I needed you?

[mkeiser]

I tried this and ended up snapping the brace. Probably not enough heat and too much caveman. I ended up ordering the HPA modified center mount. I appreciate the DIY tho!